Kobayashi Mariko, Suzuki Fumitaka, Akuta Norio, Tsubota Akihito, Ikeda Kenji, Arase Yasuji, Suzuki Yoshiyuki, Saitoh Satoshi, Kobayashi Masahiro, Hosaka Tetsuya, Someya Takashi, Matsuda Marie, Sato Junko, Miyakawa Yuzo, Kumada Hiromitsu
Research Institute for Hepatology, Toranomon Hospital, Tokyo, Japan.
J Gastroenterol Hepatol. 2005 Apr;20(4):570-6. doi: 10.1111/j.1440-1746.2005.03798.x.
Hepatitis B virus (HBV) genotype B is classified into subtype Ba with the recombination with genotype C in the precore region plus core gene and subtype Bj without recombination. Virological and clinical differences between infections with subtypes Ba and Bj, however, are yet to be determined.
During 1976 through 2001, 224 patients visited Toranomon Hospital in Tokyo, Japan who were infected with HBV genotype B. Subtypes of genotype B were determined by sequencing HBV-DNA recovered from sera for detecting recombination with genotype C.
Subtype Ba was detected in 53 patients (24%) and Bj in 167 (75%); subtypes were not able to be determined in the remaining four (1%). The only virological difference was that detection of hepatitis B e antigen at the presentation was more frequent in the patients infected with subtype Ba than those with Bj (63% vs 33%, P = 0.016). There were no differences in the distribution of liver disease of various forms between the patients infected with subtypes Ba and Bj at presentation. No differences were noted, either, in the development of liver cirrhosis or hepatocellular carcinoma, or the loss of hepatitis B surface antigen from serum, between the patients infected with subtypes Ba and Bj during follow up of up to 26 years.
Although there were some virological differences between the patients infected with subtypes Ba and Bj of HBV genotype B, they do not seem to influence the long-term clinical outcome.
乙型肝炎病毒（HBV）基因型B分为前核心区加核心基因与基因型C发生重组的Ba亚型和未发生重组的Bj亚型。然而，Ba和Bj亚型感染之间的病毒学和临床差异尚未确定。
1976年至2001年期间，224例感染HBV基因型B的患者前往日本东京虎之门医院就诊。通过对血清中回收的HBV-DNA进行测序以检测与基因型C的重组，从而确定基因型B的亚型。
53例患者（24%）检测为Ba亚型，167例（75%）为Bj亚型；其余4例（1%）无法确定亚型。唯一的病毒学差异是，Ba亚型感染患者在就诊时乙肝e抗原的检出率高于Bj亚型感染患者（63%对33%，P = 0.016）。就诊时，Ba和Bj亚型感染患者之间各种形式肝病的分布没有差异。在长达26年的随访中，Ba和Bj亚型感染患者在肝硬化或肝细胞癌的发生，或血清中乙肝表面抗原的消失方面也没有差异。
虽然HBV基因型B的Ba和Bj亚型感染患者之间存在一些病毒学差异，但它们似乎并不影响长期临床结局。
